1. Field of the Invention
The present invention relates to the composition of a novel lead-free solder alloy.
2. Description of the Related Art
In the solder alloy, lead has been conventionally an important metal for diluting tin to improve flow factor and wettability. Obviating the use of lead, a toxic, heavy metal, is preferred in consideration of working environments in which soldered products are used, and the earth friendly to which solder is released. Avoiding the use of lead in solder alloy is thus noticeable practice.
When a lead-free solder alloy is formed, the alloy is required to have wettability to metals to be soldered. Tin having such wettability is an indispensable metal as a base material. In the formation of a lead-free solder alloy, it is important to fully exploit the property of tin and to determine the content of an additive metal for the purpose of imparting, to the lead-free solder alloy, strength and flexibility as good as those of the conventional tin-lead eutectic alloy.